【Introduction to Traditional Crafts】 ~Owari Shippo (Aichi Prefecture)~
2023.01.10 
About Japan's Traditional Crafts
【name】
Owari Shippo
【Production area of Owari Shippo】
Ama City and Nagoya City in Aichi Prefecture
【What is Owari Shippo?】
Pottery produced in Ama City and around Nagoya City in Aichi Prefecture.
Gorgeous designs of flowers, birds, and landscapes are drawn, and the seven kinds of precious treasures in Buddhism (gold, silver, lapis lazuli, agate, mantis shrimp, pearls, and Maye) are scattered.
For some reason, it is called “Seven Treasures”.
Vases and plates are representative, but accessories are also popular nowadays.
In April 1995, it was designated as a traditional craft.
【Features of Owari Shippo】
It uses a metal base such as silver or copper, and by applying a colored glassy glaze to the surface, it is characterized by “gorgeous patterns such as flowers and birds” and “glittering colors.”
In addition, various techniques are used, as listed below.
By fusing several techniques, new techniques are also created.
・Wired Shippo
This is the basic technique of shippo.
After drawing a sketch on the metal base, a metal line is erected along the drawing to create an outline.
It is glazed, fired, and finally polished.
・Wireless Shippo
As the word “wireless” suggests, this technique does not use metal wires from the beginning.
Alternatively, remove the metal wire before baking.
With the invention of wireless cloisonne, it became possible to express the technique of gradation.
・Moriage Shippo
In the polishing process, which will be described later, the glaze is applied before firing to make it look three-dimensional.
・Empty Shippo
A technique that makes it look like a glass product after completion.
The base material is made of copper, and after the silver wire is set up, a transparent glaze is applied and fired.
In this method, the copper substrate is removed by corroding with acid after polishing.
Owari shippo made by craftsmen using these techniques continues to fascinate many people with its unique splendor.
【History of Owari Shippo】
Shippo is said to have originated in Egypt around 3000 BC.
Later, it was introduced from Europe and mainland China.
The oldest surviving shippo is a coffin ornament that was excavated from an ancient burial mound in Nara.
Around 1830-1844, shippo plates were imported by Dutch ships.
Tsunekichi Kaji, a feudal retainer of Owari Province, used the plate as a clue to discover the manufacturing method of shippo and continued to improve it.
Tsunekichi Kaji established the manufacturing method of shippo, and it took root as an industry by the second and third sons of farmers.
As the manufacturing method gradually spread, the shippo made in the present-day Owari region of Aichi Prefecture came to be called ‘Owari Shippo.’
Owari Shippo does not include the name of the creator on the finished product.
It may be related to the fact that the beginning was an industry that supported the village and that it was not a work of art by craftsmen.
Japanese Shippo was exhibited for the first time at the Paris Exposition held in 1867.
With high evaluation, the name will be known all over the world.
During World War II, the manufacture and sale of luxury goods such as fine textiles and ornaments was prohibited.
Production of Owari Shippo was also discontinued, and for the first time, it was in danger of survival.
However, Shinji Yoshino, who served as the governor of Aichi Prefecture from 1943, ordered shippo to be fired, albeit on a small scale, saying, “Because it is an important industry for the region.”
As a result, Owari Shippo was able to make a comeback.
【Production process of Owari Shippo】
Each process up to completion requires specialized skills.
It is a division of labor system, and it is common for the work to be done by specialized craftsmen.
①Creating base material
referring source：Traditional Craft Aoyama Square
Copper plate is mainly used for the substrate.
There are two ways to form the copper plate.
・Hand squeezing
A method in which a craftsman shapes a copper plate while beating it with a mallet.
・Mechanical drawing
A method of molding using a lathe (or press) and iron rods.
②Underglazing
It is a process of drawing a rough sketch on the surface that has been prepared by using one of two methods: “drawing directly with ink” or “painting after applying white glaze to the entire surface and baking it.”
In addition to these, a new technique using a plastic mold engraved with a pattern has recently been used.
Compared to manual work, the speed and time can be shortened, so the efficiency of work is progressing.
③Wire
This is the process of planting the silver wire using glue along the drawn sketch.
Glue is called “shirokyu”, which is made by grinding orchid bulbs after drying them.
④Glazing
In this process, glaze is applied between the lines where the silver wires are planted.
Owari Shippo, which is characterized by gorgeous patterns, has dozens of different glazes to accommodate various color schemes.
In order to bring out colors that cannot be found anywhere else, the potters are very creative in how they mix the glaze.
You can enjoy the individuality of the pottery and the craftsmen, as the colors will be completely different depending on the composition and technique.
“Line attachment” and “glazing” are done manually by craftsmen.
This is because even in modern times, it is difficult to mechanize these two processes.
⑤Firing
It is a process of firing in an electric kiln at 700-800℃ for 10-15 minutes.
The glaze melts during firing, creating a difference in height from the metal wire, so the process is repeated until the height is the same.
The firing temperature and time will vary depending on factors such as the size and shape of the product and the glaze used.
⑥Polishing
The height difference between the metal wire and the glaze is eliminated during firing, but it is not completely flat.
Therefore, polishing work is necessary to make it smooth without unevenness.
First, it is polished with a whetstone, and then tin oxide is used to give it a luster.
By continuing to polish, the metal lines that form the outline of the design become visible.
In some cases, they are also polished with industrial diamonds.
⑦Attaching a ring
This is the process of attaching a covering ring such as silver plating to the unprocessed part.